An example of an internal Combustion engine having a throttle valve of the general type has been described in DE-OS No. 37 11 779. The throttle valve described therein is controlled by a conventional mechanical throttle linkage and an electronic servomotor. Electronic control of the gas pedal is achieved by using the servomotor to control the throttle valve operation between the phases of the completely closed position and the maximum open position. When the gas pedal is not being depressed, the mechanical throttle linkage will fully close the throttle valve. In the event of a failure of the servomotor, the throttle valve is still fully operable by the manual override capability of the mechanical throttle valve linkage.
However, this servomotor controlled throttle valve operation does not adequately control idle fuel injection. For instance, when the throttle valve is completely closed (i.e. during idle conditions), it is being controlled by the mechanical linkage rather than the servomotor. The engine does not respond quickly to a sudden depression of the gas pedal because of the slight delay inherent in the mechanical linkage involved in opening the throttle valve.
It is desirable to keep the throttle valve open a slight degree (preferably between 0.degree.-10.degree.) during idle conditions to ensure that the engine remains ready to move, and to allow the throttle valve to completely close when the engine is turned off.
Imprecise or inadequate control of the throttle valve usually results in a momentary stall during an acceleration from the idle condition. Thus, there is a definite need in the art to improve engine operating engine performance, and fuel efficiency through more precise control of throttle valve operation.